Fraud detection system and method

ABSTRACT

A system and method is described for detecting a foreign object such as a skimmer placed adjacent to a bezel for a magnetic card reader device, as used in automatic teller machines and gas pumps. At least two sensors are mounted adjacent to the bezel. Each sensor provides a signal that varies when a skimmer is mounted adjacent to the bezel. A controller receive measurement signals from the sensors, and generates an alarm signal when the measurement signals differ from associated predetermined baseline signals by at least associated predetermined thresholds. The alarm signal indicates that a foreign object has been detected adjacent the bezel. The sensors may be capacitive, time of flight, spectral, radar, and/or inductive. The capacitive sensors may include three or more plates, forming multiple capacitive pairs, each capacitive pair effectively forming a separate sensor.

FIELD

This disclosure relates generally to an improved fraud detection systemand method for use with equipment, such as automatic teller machines andgas pumps, that read information from a magnetic stripe card.

BACKGROUND

Unauthorized reading of card data, such as data encoded on a magneticstripe of a customer' debit or credit card, while the card is being used(“card skimming”), is a known type of fraud. Card skimming is most oftendone by adding a skimmer, i.e., an assembly including a separatemagnetic read head, to the front fascia of an automated teller machine(ATM) or gas pump which reads the magnetic stripe on the customer's cardas the card is inserted or removed from the ATM or gas pump.

Current systems and methods for detecting skimmers are based on the useof a single capacitive sensor. As card skimming technology has becomemore sophisticated, the detection threshold of the single capacitivesensor-based system has been changed in a way which could result in morefalse alerts. In addition, single capacitive sensor-based systems mayalso be prone to cancellation effects resulting in the failure to detecta skimmer mounted on an ATM or gas pump.

Accordingly, there is a need for a fraud detection system and methodwhich addresses the drawbacks identified above.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description, given by way of example and notintended to limit the present disclosure solely thereto, will best beunderstood in conjunction with the accompanying drawings in which:

FIG. 1 is a front view of an automatic teller machine card reader bezel;

FIG. 2A is a rear view of an automatic teller machine card reader bezelshowing the placement of capacitive plates for use in the frauddetection system and method of the present disclosure, and a FIG. 2B isa block diagram showing the interconnection of the capacitive plates andassociated controller;

FIG. 3 is a rear view of an automatic teller machine card reader bezelshowing the placement of time of a flight sensor for use in the frauddetection system and method of the present disclosure;

FIG. 4 is a rear view of an automatic teller machine card reader bezelshowing the placement of a spectral response sensor for use in the frauddetection system and method of the present disclosure;

FIG. 5 is a rear view of an automatic teller machine card reader bezelshowing the placement of a radar sensor for use in the fraud detectionsystem and method of the present disclosure;

FIG. 6 is a rear view of an automatic teller machine card reader bezelshowing the placement of an inductive sensor for use in the frauddetection system and method of the present disclosure;

FIG. 7 is a block diagram of the fraud detection system and method ofthe present disclosure; and

FIG. 8 is a flow chart showing the operation of the fraud detectionsystem and method of the present disclosure.

DETAILED DESCRIPTION

In the present disclosure, like reference numbers refer to like elementsthroughout the drawings, which illustrate various exemplary embodimentsof the present disclosure.

As known in the art, automated teller machines (ATMs) typically includea graphic user interface for displaying information, a keypad forreceiving user inputs, a bezel which has a card slot for accepting andguiding a user's credit/debit card into a card reader mechanism, a slotfor dispensing a printed receipt, a cash dispensing slot for withdrawingmoney, and a cash deposit slot for depositing money. A controller isprogrammed to control the operation of the ATM and to manage externalcommunications with a remote host. ATMs of this nature are well knownand will not be described in detail herein. A gas pump which acceptscredit/debit cards includes similar elements, except for the cashdispensing and deposit slots. Skimmers are typically mounted by thieveson or over the bezel of the ATM, gas pump, or other type of magneticcard reader device and are designed in a way to match or hide theoriginal bezel so that a user does not realize that the skimmer is inplace on the ATM or gas pump before the use thereof.

Referring now to FIG. 1, a front (exterior) portion 110 of an examplebezel 100 is shown. Bezel 100 is typically a separate part, e.g., amolded plastic part, that covers the magnetic card reader device. Bezel100 includes a slot 130 for inserting a magnetic stripe card and acavity 140 which provides space for use in inserting and withdrawing themagnetic stripe card. The bezel 100 shown in FIG. 1 is an example of abezel to cover a magnetic card reader device used on, e.g., an ATM orgas pump, but the particular shape or configuration of a bezel isarbitrary (i.e., dependent on the particular implementation) and thusnot material with respect to the operation of the systems and method ofthe present disclosure. The systems and method of the present disclosureare applicable to any type of machine or equipment having an integralmagnetic card reader device for reading a magnetic stripe card such as acredit or debit card via a slot (or other cavity for receiving amagnetic stripe card) in order to detect the placement of a skimmerplaced over or near the card slot thereof.

Referring now to FIG. 2A, a rear (interior) portion 120 of bezel 100 isshown including plate areas for forming capacitive sensors. Inparticular, in accordance with one aspect of the present invention, aseries of capacitive plates 200 a, 200 b, . . . 200 n are placed invarious positions on an inner surface 210 of bezel 100, where n is anumber greater than or equal to two (2). As shown in FIG. 2B, each ofthe capacitive plates 210, 211, 212 (corresponding to capacitive plates200 a, 200 b, . . . 200 n in FIG. 2B) is connected directly to a firstswitch (S1) 220 and to a second switch (S2), which each operate underthe control of a controller 250. First switch 220 is also connected to adrive circuit 230 and is configured to selectively connect drive circuit230 to one of the capacitive plates 210, 211, 212 based on an input fromcontroller 250. Drive circuit 230 outputs a predetermined alternatingcurrent (AC) signal (a reference signal) to the selected one of thecapacitive plates 210, 211, 212 as the transmit plate. Second switch 200is also connected to a detection circuit 240 and is configured toselectively connect one of the capacitive plates 210, 211, 212 to thedetection circuit 240 based on an input from controller 250 (theselected plate acting as the receive plate). Detection circuit 240 isconfigured to monitor the phase and/or magnitude of the signal receivedfrom each capacitive plate 210, 211, 212 (the reference signal) and isconnected to controller 250 to provide an indication of the measuredsignal to controller 250. In FIG. 2B, separate components are shown forthe first switch 220, the second switch 221, the drive circuit 230, thedetection circuit 240, and the controller 250. As one of ordinary skillin the art will readily recognize, these circuits may all be provided aspart of the functionality of a single controller (represented by thedotted line 260), integrated into a controller, or in other combinationsthereof.

When controller 250 determines that the phase and/or magnitude of thereceived signal has changed from the predetermined value (i.e., abaseline value determined when no additional structure is placed overthe front of bezel 100), it can indicate that some structure (e.g., aforeign object of some sort) has been placed over the front portion ofbezel 100. This occurs because air and portions of bezel 100 fallbetween each plate pair and act as a dielectric (with a fixed dielectricconstant), and a changed signal at the receive plate indicates a changein the dielectric. By using more than two plates which can each act as atransmit plate or a receive plate, a set of three plates provides threedifferent capacitive sensor combinations (plate pairs), a set of fourplates provides six different capacitive sensor combinations, a set offive plates provides ten different capacitive sensor combinations, etc.Rather than just a single capacitive sensor focusing on one area of thebezel (i.e., when only two plates are used), the use of multiplecapacitor plates placed in and around the rear of the bezel, as shown inFIG. 2A, provides a much greater detection zone for materials placedover the front portion of the bezel 100. However, only two plates may beused when additional sensors based on one or more different technologiesare also used, as discussed herein. By sequentially applying a fixedsignal to each transmit plate, and measuring the signal at eachassociated receive plate, the signal received at each receive plate willhave a predetermined magnitude and phase in normal operation. However,if additional materials are inserted between any of the plates pairs(e.g., by placing structure over the front face of the bezel 100), thedielectric constant of each plate pair will change and the magnitude andphase of the signal received at the receive plate, as measured bydetection circuit 240, will also change. When this change persists orwhen the received signals from a number of transmit plates change, itcan indicate that some structure, e.g., a skimmer, has been placed overthe face of bezel 100. This provides a much greater detection area thanprevious solutions, and makes it much more difficult to design a skimmerstructure that could avoid detection when only one or two capacitivesensors are provided.

Referring now to FIG. 3, a rear portion 120 of bezel 100 is shownincluding a time of flight sensor 300. Time of flight sensor 300 iscoupled to a controller 710, as shown in FIG. 7 below. Time of flightsensor 300 is mounted adjacent to an aperture 110 (shown in FIG. 1) andat a point where light emitted from the sensor 300 through the aperture110 will reflect back from another part of the front of bezel 100 or afront portion of the associated ATM machine (or gas pump). For example,time of flight sensor 300 may be positioned along the top lip of thebezel 100 facing down (so that emitted light will travel downwards). Atime of flight sensor measures a distance of an object in the path ofits emitted light based on the time of reflection from that object. Timeof flight sensor 301 provides a predetermined output (a referenceoutput) when no structure is added to the face of bezel 100. Any changein the output from time of flight sensor 301 indicates that somestructure, such as a skimmer, has been placed over the front face 101 ofbezel 100 and thereby interrupted the sensor's light path. By combiningthe use of capacitive sensors, as shown in FIGS. 2A and 2B, with thetime of flight sensor shown in FIG. 3, an additional level of confidencewill be provided in determining when a skinner has been placed over thefront of bezel 100. In some cases, a time of flight sensor may be usedalone, e.g., when the bezel 100 is configured in a manner in which askimmer may only be located in one place, but in most cases it ispreferable to use both capacitive sensors as set forth above and one ormore time of flight sensors.

Referring now to FIG. 4, a rear portion 120 of bezel 100 is shownincluding a spectral sensor 400. A spectral sensor uses a lighttransmitter and receiver with various filters to measure the spectrum ofreflected light, allowing multiple feedback capabilities on a singlesensor. Spectral sensor 400 is coupled to controller 710, as shown inFIG. 7, and is mounted in a position where It detects, based on a changein light level, if the light at the front face of bezel 100 falls belowa predetermined minimum light level, thereby indicating that the frontface of bezel 100 has been covered, e.g. by a skimmer. Spectral sensor400 may also be used as a reflective sensor, detecting a reflectivepattern when the front face of bezel 100 is covered, and as a materialanalysis sensor, providing different responses over the reflected lightspectrums, depending on the composition of the material placed over thefront face of bezel. The use of a spectral sensor 400, in addition tothe capacitive sensors and/or one or more time of flight sensorsdiscussed above, provides an added level of confidence that any skimmerplaced over the front face of bezel 100 will be detected without anundue number of false alarms.

Referring now to FIG. 5, a rear portion 120 of bezel 100 is shownincluding a radar sensor 500 that is coupled to a controller 710 asshown in FIG. 7. Radar sensor 500 transmits and receives radio waves ina forward direction through the body of bezel 100 in order to generate athree-dimensional image of the area around outside of the bezel 100.Radar sensor 500 continually monitors bezel 100, and by incorporatingimage processing techniques into controller 710, a predeterminedbaseline image of the bezel 100 can be compared in real-time to signalsfrom radar sensor 400 in order to detect any changes from that baselineimage, thereby indicating that some structure has been added to thefront of bezel 100. Radar sensor 500 provides an advantage in that noaperture is required in bezel 100 for use thereof, because the radiowaves emitted by radar sensor 500 pass through the body of bezel 100. Aswith the spectral sensor, the addition of a radar sensor to a systemusing capacitive sensors, one or more time of flight sensors, and/or oneor more spectral sensors provides an added level of confidence that anyskimmer placed over the front face of bezel 100 will be detected withoutan undue number of false alarms.

Referring now to FIG. 6, a rear portion 120 of bezel 100 is shownincluding a inductive sensor 600 that is coupled to a controller 710 asshown in FIG. 7. Inductive sensor 600 acts as a proximity sensor,detecting metallic objects placed within the magnetic field. This isparticularly useful in detecting the metallic portions of skimmers,e.g., read-heads, placed over bezel 100. Although only one inductivesensor 600 is shown in FIG. 6, more than one sensor may be employed,each sensor positioned on the rear of bezel 100 in areas close to wherea read-head of a skimmer could be positioned, e.g., in and around theslot area 130 of the bezel 100. As with the radar sensor 500, inductivesensor 600 does not require an aperture in bezel 100 to operate. Theaddition of an inductive sensor to a system using capacitive sensors,one or more time of flight sensors, one or more spectral sensors, and/orone or more radar sensors provides an added level of confidence that anyskimmer placed over the front face of bezel 100 will be detected withoutan undue number of false alarms.

Referring now to FIG. 7, a block diagram shows the interconnection ofthe various sensors with a controller 710. Controller 710 is shown as asingle element in FIG. 7, but may also consist of a number of separatecomponents that operate together to provide the required functionality.In particular, at least three capacitive plates 210, 211, 212 are eachseparately connected to controller 710. Controller 710 is configured inthe manner shown in FIG. 2B discussed above to allow one of thecapacitive plates 210, 211, 212 to be selectively set as a transmitplate and the other to be set as a receive plate. Controller 710 isconfigure to step through each possible combination of plates andcompare the phase and/or magnitude of each receive (measurement) signal(i.e., the signal found at each receive plate) with a stored baselinevalue. When a receive signal differs from the stored (predetermined)baseline signal by at least a predetermined amount (i.e., apredetermined threshold), it is an indication that some additionalstructure (e.g., a skimmer) has been placed on the front of bezel 100.In addition, one or more of a time of flight sensor 300, a spectralsensor 400, a radar sensor 500, and an inductive sensor 600 may also becoupled to controller 710. Controller 710 is configured to process theinputs received from each sensor, as discussed above, and determinewhether each of the signals vary from a respective predeterminedbaseline level by a predetermined threshold to determine if a structuresuch as a skimmer has been placed over the front face of bezel 100.Controller 710 is configured to determine that structure of some sort(e.g., a skimmer) has been found pursuant to the steps shown inflowchart 800 in FIG. 8 discussed below. Once controller 710 doesdetermine that a skimmer or other structure has been placed over thefront face of bezel 100, an alarm signal is generated on output 720.This alarm signal can be routed to the main control circuitry for theassociated ATM or gas pump in order to cease operations until a repairis performed. This signal may also be forwarded (via circuitry notshown) to a main control location for the associated ATM or gas pump, inorder to generate a repair order for that ATM or gas pump. In somecases, the alarm signal may be provided to an electronically controlledshutter mounted over the card slot which closes upon receipt of thealarm, preventing any insertion of a magnetic stripe card into the cardslot. In other cases, a message may be displayed on a display of the ATMor gas pump which states that the ATM or gas pump is out of order and nocard should be inserted into the card slot.

Referring now to FIG. 8, a flowchart 800 is shown demonstrating theoperation of controller 710. First, at step 810, the complete system iscalibrated, e.g., at assembly or installation of the associated ATM orgas pump, to determine a baseline level for each sensor in a state whenit is known that there no extra structure is mounted over an externalface of the bezel. As discussed above, for each capacitive plate pair,the baseline level may be the amplitude or phase of the signal at thereceive plate. For a time of flight sensor, the baseline level is asignal indicating a distance from the sensor to the nearest structure(as seen through the associated aperture in bezel 100). For a spectralsensor, the baseline level is, for example, signal indicating a level oflight at the sensor. For a radar sensor, the baseline level is an imageof the front part of bezel 100. For the inductive sensor, the baselinelevel is a signal indicating the level of nearby metallic structures.Once the ATM or gas pump is put into service, processor 710 continuallyreceives or determines each sensor output (step 830) and compares theoutput of each sensor to the predetermined baseline level. When noexcessive variation from the associated baseline level is found in anyof the sensor outputs, processing reverts to step 820. When a variationfrom a baseline level beyond a preset threshold for each sensor is foundin a majority of the sensor outputs, processor 710 then sets an alarmsignal (e.g., on line 720) as discussed above indicating that somestructure has been placed over the face of bezel 100. In this manner,the system requires at least two different sensors that are preferablybased on different technologies (e.g., at least two picked from the setof capacitive, time of flight, spectral, radar, and inductive) to varyfrom an associated baseline level beyond a predetermined threshold inorder to generate an alarm. The alarm signal is preferably generatedbased on a majority vote scheme. The majority vote scheme provides anadded confidence that no false alarms will be generated because thepreset threshold for each sensor can be set at a higher level than wouldbe used if only that particular sensor were in use. In addition, thepreset threshold for each sensor can be adjusted by predeterminedweighting factors. In an alternative embodiment, the alarm signal may begenerated based on a predetermined detection algorithm. Thepredetermined thresholds for each sensor are preferably set atconfiguration along with the associated baseline levels. In a furtherembodiment, processor 710 may also be programmed to use machine learningto vary each sensor's threshold value based on conditions at theinstallation location, for example, environmental variations due tolighting levels, etc.

Although the present disclosure has been particularly shown anddescribed with reference to the preferred embodiments and variousaspects thereof, it will be appreciated by those of ordinary skill inthe art that various changes and modifications may be made withoutdeparting from the spirit and scope of the disclosure. It is intendedthat the appended claims be interpreted as including the embodimentsdescribed herein, the alternatives mentioned above, and all equivalentsthereto.

1. A system for detecting a foreign object, comprising: a first sensormounted adjacent to a bezel for a magnetic card reader device, the firstsensor providing a first signal that varies when a foreign object isplaced adjacent to an exterior portion of the bezel; a second sensormounted adjacent to the bezel, the second sensor providing a secondsignal that varies when a foreign object is placed adjacent to theexterior portion of the bezel, the second sensor operating according toa different technology than the first sensor; and a controller coupledto the first sensor and the second sensor, the controller configured toreceive the first signal and the second signal and to generate a firstalarm signal when the first signal differs from a first predeterminedbaseline signal by at least a first predetermined threshold and thesecond signal differs from a second predetermined baseline signal by atleast a second predetermined threshold, the first alarm signalindicating that a foreign object has been detected.
 2. The system ofclaim 1, further comprising: a third sensor mounted adjacent to thebezel, the third sensor providing a third signal that varies when aforeign object is placed adjacent to the exterior portion of the bezel,the third sensor operating according to a different technology than thefirst sensor and the second sensor; and wherein the controller iscoupled to the third sensor to receive the third signal therefrom andthe controller is configured to determine if the third signal differsfrom a third predetermined baseline signal by a third predeterminedthreshold, and to generate a second alarm signal when at least two ofthe first signal, the second signal, and the third signal differ fromassociated predetermined baseline signals by at least associatedpredetermined thresholds.
 3. The system of claim 2, further comprising:a fourth sensor mounted adjacent to the bezel, the fourth sensorproviding a fourth signal that varies when a foreign object is placedadjacent to the exterior portion of the bezel, the fourth sensoroperating according to a different technology than the first sensor, thesecond sensor, and the third sensor; and wherein the controller iscoupled to the fourth sensor to receive the fourth signal therefrom andthe controller configured to determine if the fourth signal differs froma fourth predetermined baseline signal by a fourth predeterminedthreshold, and to generate a third alarm signal when at least three ofthe first signal, the second signal, the third signal, and the fourthsignal differ from associated predetermined baseline signals by at leastthe associated predetermined thresholds.
 4. The system of claim 3,further comprising: a fifth sensor mounted adjacent to the bezel, thefifth sensor providing a fifth signal that varies when a foreign objectis placed adjacent to the exterior portion of the bezel, the fifthsensor operating according to a different technology than the firstsensor, the second sensor, the third sensor, and the fourth sensor; andwherein the controller is coupled to the fifth sensor to receive thefifth signal therefrom and the controller configured to determine if thefifth signal differs from a fifth predetermined baseline signal by afifth predetermined threshold, and to generate a fourth alarm signalwhen at least three of the first signal, the second signal, the thirdsignal, the fourth signal, and the fifth signal differ from associatedpredetermined baseline signals by at least associated predeterminedthresholds.
 5. The system of claim 1, wherein the first sensor iscapacitive-based and includes two plates mounted adjacent to the bezel,each of the plates coupled to the controller, and wherein the controlleris configured to apply a reference signal to one of the two plates andto receive a measurement signal from the other of the two plates,wherein the first signal corresponds to the measurement signal.
 6. Thesystem of claim 5, wherein the second sensor is one of a time of flightsensor, a spectral sensor, a radar sensor, and an inductive sensor. 7.The system of claim 1, wherein the first sensor is capacitive-based andincludes at least three plates mounted adjacent to the bezel, each ofthe three plates coupled to the controller, the at least three platesforming capacitive pairs with each pair comprising two of the at leastthree plates, and wherein the controller is configured to sequentiallyapply a reference signal to a selected one of the two plates in eachcapacitive pair and to receive a measurement signal from the other ofthe two plates in each capacitive pair, and wherein the measurementsignal from each capacitive pair corresponds to the first signal.
 8. Thesystem of claim 1, wherein the first sensor is one of a time of flightsensor, a spectral sensor, a radar sensor, and an inductive sensor. 9.The system of claim 8, wherein the second sensor is another of a time offlight sensor, a spectral sensor, a radar sensor, and an inductivesensor.
 10. A system for detecting a foreign object, comprising: acapacitive sensor including at least three plates mounted adjacent to abezel for a magnetic card reader device, the at least three platesforming capacitive pairs with each pair comprising two of the at leastthree plates; and a controller separately coupled to each of the atleast three plates, the controller configured to sequentially apply areference signal to a selected one of the two plates in each capacitivepair and to receive a measurement signal from the other of the twoplates in each capacitive pair and to generate an alarm signal when amajority of the measurement signals differ from associated predeterminedbaseline signals by at least associated predetermined thresholds, thealarm signal indicating that a foreign object has been detected.
 11. Thesystem of claim 10, further comprising: a time of flight sensor mountedadjacent to the bezel, the time of flight sensor providing a time offlight signal that varies when a foreign object is placed adjacent tothe bezel; and wherein the controller is coupled to the time of flightsensor, the controller configured to receive the time of flight signalto generate the alarm signal when a majority of the measurement signalsand the time of flight signal differ from associated predeterminedbaseline signals by at least associated predetermined thresholds. 12.The system of claim 11, further comprising: a third sensor mountedadjacent to the bezel, the third sensor one of a spectral sensor, aradar sensor, and an inductive sensor, the third sensor providing athird measurement signal that varies when a foreign object is placedadjacent to the bezel; and wherein the controller is coupled to thethird sensor, the controller configured to receive the third measurementsignal from the third sensor to generate the alarm signal when amajority of the measurement signals the time of flight signal, and thethird measurement signal differ from associated predetermined baselinesignals by at least associated predetermined thresholds.
 13. The systemof claim 10, further comprising: a spectral sensor mounted adjacent tothe bezel, the spectral sensor providing a spectral signal that varieswhen a foreign object is placed adjacent to the bezel; and wherein thecontroller is coupled to the spectral sensor, the controller configuredto receive the spectral signal to generate the alarm signal when amajority of the measurement signals and the spectral signal differ fromassociated predetermined baseline signals by at least associatedpredetermined thresholds.
 14. The system of claim 13, furthercomprising: a third sensor mounted adjacent to the bezel, the thirdsensor one of a time of flight sensor, a radar sensor, and an inductivesensor, the third sensor providing a third measurement signal thatvaries when a foreign object is placed adjacent to the bezel; andwherein the controller is coupled to the third sensor, the controllerconfigured to receive the third measurement signal from the third sensorand to generate the alarm signal when a majority of the measurementsignals, the spectral signal, and the third measurement signal differfrom associated predetermined baseline signals by at least associatedpredetermined thresholds.
 15. The system of claim 10, furthercomprising: a radar sensor mounted adjacent to the bezel, the radarsensor providing a radar signal that varies when a foreign object isplaced adjacent to the bezel; and wherein the controller is coupled tothe radar sensor, the controller configured to receive the radar signaland to generate the alarm signal when a majority of the measurementsignals and the radar signal differ from associated predeterminedbaseline signals by at least associated predetermined thresholds. 16.The system of claim 15, further comprising: a third sensor mountedadjacent to the bezel, the third sensor one of a time of flight sensor,a spectral sensor, and an inductive sensor, the third sensor providing athird measurement signal that varies when a foreign object is placedadjacent to the bezel; and wherein the controller is coupled to thethird sensor, the controller configured to receive the third measurementsignal from the third sensor and to generate the alarm signal when amajority of the measurement signals, the spectral signal, and the thirdmeasurement signal differ from associated predetermined baseline signalsby at least associated predetermined thresholds.
 17. The system of claim10, further comprising: an inductive sensor mounted adjacent to thebezel, the inductive sensor providing an inductive signal that varieswhen a foreign object is placed adjacent to the bezel; and wherein thecontroller is coupled to the inductive sensor, the controller configuredto receive the inductive signal and to generate the alarm signal when amajority of the measurement signals and the inductive signal differ fromassociated predetermined baseline signals by at least associatedpredetermined thresholds.
 18. The system of claim 17, furthercomprising: a third sensor mounted adjacent to the bezel, the thirdsensor one of a time of flight sensor, a spectral sensor, and a radarsensor, the third sensor providing a third measurement signal thatvaries when a foreign object is placed adjacent to the bezel; andwherein the controller is coupled to the third sensor, the controllerconfigured to receive the third measurement signal from the third sensorand to generate the alarm signal when a majority of the measurementsignals, the spectral signal from, and the third measurement signaldiffer from associated predetermined baseline signals by at leastassociated predetermined thresholds.
 19. A method for detecting aforeign object placed adjacent to a bezel for a magnetic card readerdevice, comprising the steps of: calibrating each of at least twosensors mounted adjacent to a bezel for a magnetic card reader device todetermine an associated baseline level for each of the at least twosensors, each of the at least two sensors providing an associatedmeasurement signal that varies when a foreign object is placed adjacentto the bezel, each of the at least two sensors operating according to adifferent technology than the others of the at least two sensors;monitoring the measurement signals from each of the at least twosensors; and generating an alarm signal indicating that a foreign objecthas been detected adjacent to the bezel when a majority of themeasurement signals from the at least two sensors differ from associatedbaseline levels by at least associated predetermined thresholds.
 20. Themethod of claim 19, wherein the calibrating step further comprisesdetermining the associated predetermined threshold for each of the atleast two sensors.